BackgroundAntibiotic resistance is rising in important bacterial pathogens. Phage therapy (PT), the use of bacterial viruses infecting the pathogen in a species-specific way, is a potential alternative.MethodT4-like coliphages or a commercial Russian coliphage product or placebo was orally given over 4 days to Bangladeshi children hospitalized with acute bacterial diarrhea. Safety of oral phage was assessed clinically and by functional tests; coliphage and Escherichia coli titers and enteropathogens were determined in stool and quantitative diarrhea parameters (stool output, stool frequency) were measured. Stool microbiota was studied by 16S rRNA gene sequencing; the genomes of four fecal Streptococcus isolates were sequenced.FindingsNo adverse events attributable to oral phage application were observed (primary safety outcome). Fecal coliphage was increased in treated over control children, but the titers did not show substantial intestinal phage replication (secondary microbiology outcome). 60% of the children suffered from a microbiologically proven E. coli diarrhea; the most frequent diagnosis was ETEC infections. Bacterial co-pathogens were also detected. Half of the patients contained phage-susceptible E. coli colonies in the stool. E. coli represented less than 5% of fecal bacteria. Stool ETEC titers showed only a short-lived peak and were otherwise close to the replication threshold determined for T4 phage in vitro. An interim analysis after the enrollment of 120 patients showed no amelioration in quantitative diarrhea parameter by PT over standard care (tertiary clinical outcome). Stool microbiota was characterized by an overgrowth with Streptococcus belonging to the Streptococcus gallolyticus and Streptococcus salivarius species groups, their abundance correlated with quantitative diarrhea outcome, but genome sequencing did not identify virulence genes.InterpretationOral coliphages showed a safe gut transit in children, but failed to achieve intestinal amplification and to improve diarrhea outcome, possibly due to insufficient phage coverage and too low E. coli pathogen titers requiring higher oral phage doses. More knowledge is needed on in vivo phage–bacterium interaction and the role of E. coli in childhood diarrhea for successful PT.FundingThe study was supported by a grant from . The trial was registered with Identifier NCT00937274 at ClinicalTrials.gov.

The genomic diversity of 99 T4-like coliphages was investigated by sequencing an equimolar mixture with Illumina technology and screening them against different databases for horizontal gene transfer and undesired genes. A 9-phage cocktail was given to 15 healthy adults from Bangladesh at a dose of 3×10(9) and 3×10(7) plaque-forming units and placebo respectively. Phages were detected in 64% of the stool samples when subjects were treated with higher titer phage, compared to 30% and 28% with lower-titer phage and placebo, respectively. No Escherichia coli was present in initial stool samples, and no amplification of phage was observed. One percent of the administered oral phage was recovered from the feces. No adverse events were observed by self-report, clinical examination, or from laboratory tests for liver, kidney, and hematology function. No impact of oral phage was seen on the fecal microbiota composition with respect to bacterial 16S rRNA from stool.

Phage therapy has a long tradition in Eastern Europe, where preparations are comprised of complex phage cocktails whose compositions have not been described. We investigated the composition of a phage cocktail from the Russian pharmaceutical company Microgen targeting Escherichia coli/Proteus infections. Electron microscopy identified six phage types, with numerically T7-like phages dominating over T4-like phages. A metagenomic approach using taxonomical classification, reference mapping and de novo assembly identified 18 distinct phage types, including 7 genera of Podoviridae, 2 established and 2 proposed genera of Myoviridae, and 2 genera of Siphoviridae. De novo assembly yielded 7 contigs greater than 30 kb, including a 147-kb Myovirus genome and a 42-kb genome of a potentially new phage. Bioinformatic analysis did not reveal undesired genes and a small human volunteer trial did not associate adverse effects with oral phage exposure.

IMPORTANCE Antibiotic overuse drives antibiotic resistance. Gram-negative bacteremia is a common infection that results in substantial antibiotic use.OBJECTIVE To compare the clinical effectiveness of C-reactive protein (CRP)-guided, 7-day, and 14-day antibiotic durations 30, 60, and 90 days after treatment initiation. DESIGN, SETTING, AND PARTICIPANTS Multicenter, noninferiority, point-of-care randomized clinical trial including adults hospitalized with gram-negative bacteremia conducted in 3 Swiss tertiary care hospitals between April 2017 and May 2019, with follow-up until August 2019. Patients and physicians were blinded between randomization and antibiotic discontinuation. Adults (aged Ն18 years) were eligible for randomization on day 5 (±1 d) of microbiologically efficacious therapy for fermenting, gram-negative bacteria in blood culture(s) if they were afebrile for 24 hours without evidence for complicated infection (eg, abscess) or severe immunosuppression.INTERVENTION Randomization in a 1:1:1 ratio to an individualized CRP-guided antibiotic treatment duration (discontinuation once CRP declined by 75% from peak; n = 170), fixed 7-day treatment duration (n = 169), or fixed 14-day treatment duration (n = 165). MAIN OUTCOMES AND MEASURESThe primary outcome was the clinical failure rate at day 30, defined as the presence of at least 1 of the following, with a non-inferiority margin of 10%: recurrent bacteremia, local suppurative complication, distant complication (growth of the same organism causing the initial bacteremia), restarting gram-negative-directed antibiotic therapy due to clinical worsening suspected to be due to the initial organism, or death due to any cause. Secondary outcomes included the clinical failure rate on day 90 of follow-up. RESULTS Among 504 patients randomized (median [interquartile range] age, 79 [68][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84][85][86] years; 306 of 503 [61%] were women), 493 (98%) completed 30-day follow-up and 448 (89%) completed 90-day follow-up. Median antibiotic duration in the CRP group was 7 (interquartile range, 6-10; range, 5-28) days; 34 of the 164 patients (21%) who completed the 30-day follow-up had protocol violations related to treatment assignment. The primary outcome occurred in 4 of 164 (2.4%) patients in the CRP group, 11 of 166 (6.6%) in the 7-day group, and 9 of 163 (5.5%) in the 14-day group (difference in CRP vs 14-day group, −3.1% [1-sided 97.5% CI, −ϱ to 1.1]; P < .001; difference in 7-day vs 14-day group, 1.1% [1-sided 97.5% CI, −ϱ to 6.3]; P < .001). By day 90, clinical failure occurred in 10 of 143 patients (7.0%) in the CRP group, 16 of 151 (10.6%) in the 7-day group, and 16 of 153 (10.5%) in the 14-day group.CONCLUSIONS AND RELEVANCE Among adults with uncomplicated gram-negative bacteremia, 30-day rates of clinical failure for CRP-guided antibiotic treatment duration and fixed 7-day treatment were noninferior to fixed 14-day treatment. However, interpretation is limited by the large noninferiority margin compared with...

There is a current unmet medical need for the treatment of antibiotic-resistant infections, and in the absence of approved alternatives, some clinicians are turning to empirical ones, such as phage therapy, for compassionate treatment. Phage therapy is ideal for compassionate use due to its long-standing historical use and publications, apparent lack of adverse effects, and solid support by fundamental research. Increased media coverage and peer-reviewed articles have given rise to a more widespread familiarity with its therapeutic potential. However, compassionate phage therapy (cPT) remains limited to a small number of experimental treatment centers or associated with individual physicians and researchers. It is possible, with the creation of guidelines and a greater central coordination, that cPT could reach more of those in need, starting by increasing the availability of phages. Subsequent steps, particularly production and purification, are difficult to scale, and treatment paradigms stand highly variable between cases, or are frequently not reported. This article serves both to synopsize cPT publications to date and to discuss currently available phage sources for cPT. As the antibiotic resistance crisis continues to grow and the future of phage therapy clinical trials remains undetermined, cPT represents a possibility for bridging the gap between current treatment failures and future approved alternatives. Streamlining the process of cPT will help to ensure high quality, therapeutically-beneficial, and safe treatment.